docs: def _Function(self, t):
          """ Handle function definitions
          """
          if t.decorators is not None:
              self._fill("@")
              self._dispatch(t.decorators)
          self._fill("def "+t.name + "(")
          defaults = [None] * (len(t.argnames) - len(t.defaults)) + list(t.defaults)
          for i, arg in enumerate(zip(t.argnames, defaults)):
              self._write(arg[0])
              if arg[1] is not None:
                  self._write('=')
                  self._dispatch(arg[1])
              if i < len(t.argnames)-1:
                  self._write(', ')
          self._write(")")
          if self._single_func:
              self._do_indent = False
          self._enter()
          self._dispatch(t.code)
          self._leave()
          self._do_indent = True